For a few fleeting moments Tuesday morning, Apple briefly enjoyed a market cap in excess of $600 billion. Then, Wall Street took a tumble, dragging down a multitude of stocks - including APPL.

But don't fret if you blinked and missed Apple's latest milestone. If AAPL doesn't close at or above $643.53 today, it likely will soon. At this level, Apple has a market cap of $600 billion.

Apple is only the second company in the history of the world to boast of that achievement. Microsoft was first in 1999.

All told, it's been a stellar year for Apple. So far for 2012, Apple shares are up 57%. They're also up well over 90% from just twelve months ago. As recently as February 28, Apple enjoyed a market cap of a "measly" $500 billion.

Should Apple report another better-than-expected quarter of earnings later this month, AAPL's momentum will likely continue. The latest buzz on Wall Street is that Apple's market cap will top $1 trillion (or $1,000 per share) before the stock finally cools or levels off.